A Conductive and Wireless Power Transfer System with Wide Voltage Gains by an Asymmetrical Modulation Method

There are conductive charging and wireless power transfer (WPT) for electric vehicles (EVs), both of which are required for future charging piles and are usually separately designed and installed. However, two independent solutions increase the total cost, weight, and size of the charging pile. To address this issue, this paper proposes a conductive and wireless power transfer (CWPT) system based on resonant inductor-integrated transformers. An optimized modulation method for the multi-inverter is proposed to reduce the switching power losses. In addition, the operating modes, voltage gain, and power transfer capacity of each are presented. The primary-side AC/DC, DC/AC, transformers, and resonant circuits are shared. Only two relays and one diode rectifier are added to the conventional WPT system, which makes the overall system cost-effective and compact. A 5-kW CWPT system is built with maximum DC/DC efficiencies of 97.4% and 91.8% for conductive charging and wireless charging respectively, which demonstrates the feasibility and effectiveness of the proposed system.